Sofa



FIG. 1 is a front perspective view of a sofa in accordance with the new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a side elevation view thereof, an opposite side elevation view being a mirror image thereof; and,

FIG. 4 is a back perspective view thereof.

The broken lines shown on the sofa are understood to represent stitching. The dotted lines are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a sofa, as shown and described. 